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Set 11: Form, Structure & Sense (Advanced)

Explanation

Answer: B

PASSAGE

The phenomenon, first observed in 1962 but not fully understood until decades _______ has since been replicated in laboratories around the world.

Which choice completes the text so that it conforms to the conventions of Standard English?

A. later
B. later,✓ Correct
C. later:
D. later;

Detailed Answer Explanation

This question tests your understanding of sentence function and text organization. The phrase 'first observed in 1962 but not fully understood until decades later' is parenthetical. A comma closes this interruption before resuming with 'has since been replicated.' Each sentence in a well-constructed text serves a specific purpose. Consider what role this sentence plays in the argument: does it introduce, support, contrast, or conclude an idea? Understanding why an author includes specific sentences helps you grasp the overall argument. Each sentence should serve a clear purpose: introducing ideas, providing evidence, acknowledging counterarguments, or drawing conclusions. Identify the role to understand the structure.

Key Evidence:

• "The phenomenon, first observed in 1962"

• "has since been replicated"

Why others are wrong: C (A colon doesn't fit for closing a parenthetical phrase.), A (Missing punctuation fails to close the parenthetical phrase.), D (A semicolon is too strong; this closes a parenthetical, not an independent clause.).

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